Incandescent electric lamp



April 7, 1942. w. P. ZABEL INCANDESCENT ELECTRIC LAMP Filed Feb. 26, 1941 v lnven'tor William P. ZabeL-,; by L MW-d Hi5 AFlrorneg;

the glass.

Patented Apr. 7, 1942 INCANDESCENT ELECTRIC LAMP William P. Zabel, Cleveland Heights, Ohio, assignor to General Electric Company, a corporation of New York Application February 26, 1941, Serial No. 880,606

14 Claims.

My invention relates to electric incandescent lamps in general and more particularly to lamps of the imitation candle type.

One of'the objects of my invention is to provide a lamp of the imitation candle type which is of a simplified unitary structure which may be manufactured economically at high speeds. Further objects and advantages of my invention will appear from the following detailed description of species thereof and from the accompanying drawing.

In the drawing Fig. 1 is a vertical elevation,

in section, of a lamp comprising my invention;

Fig. 2 is an elevation of two portions of the envelope before they have been united; Fig. '3 is a side view of a part of the filament mount; Fig. 4 is an elevation of a modified portion of the mount; Figs. 5 and 6 are views similar to Fig. 1 of lamps of modified construction; and Fig. 7 is a perspective view of the internal elements of an interrupter switch employed in the lamp shown in Fig. 6.

Referring to Fig. 1, the lamp illustrated therein comprises a glass envelope having an.elongated tubular body portion ill and a flame-shaped upper end portion II, the two portions of the envelope being joined by a constricted neck portion I2. The body and end portions of the envelope are preferably made separately with constricted neck portions Ill and H respectively, as shown in .Fig. 2. The said neck portions ill and II are heated and fused together and during the fusion pressure is exerted longitudinally thereof so that the upper end of the body portion it is formed with a reversely curved portion 5 3, the neck portions l0 and H being joined to form the common neck portion indicated at it in Fig. 1.

The lamp mount comprises a conventional tipless stem M throughwhich extend lead-in wires l5, l6 The'stem is further provided with a short glass arbor I! in the form of a tube or-a solid ,rod. A stay rod l8 extends axially of the body portion ll] of the envelope and has its lower end fused and embedded into the arbor H. The said stay rod I 8 may be made of a thin U-shaped strip of metal or alloy such as a chrome iron'alloy having' a coeflicient of expansion similar to that of upper end a short tube or solid rod l9, preferably of glass having a collar or button portion 29 at its upper end located within the neck l2. A pair of conductors 2i and 22 have portions thereof fused into the periphery of the collar 20 and they extend short distances above and below the constricted neck portion i2 of the envelope.

, The flame-shaped upper end portion or chamber ll of the envelope contains an inverted. vshaped filament 23 having its ends connected to the outwardly extending ends of the conductors 2| and 22. The vertex of the filament 23 is supported by one end of a support wire 24 (Fig. 3)

. which has its opposite end embedded in the glass collar 20. The legs of the filament 23 are further supported at approximately their mid-points by the ends 'of support .wires 25, 25 which likewise have their opposite ends embedded in the collar 20.

In the form of lamp shown in Fig. 1, the body portion III of the envelope is also provided with a low-intensity filament or filaments, in this case two filaments 26 and 21, the filament 26 being connected between lead-in wire l5.and conductor 2|, and the filament 21 being connected between lead-in wire it and conductor 22. The saidfilaments 26 and 2! are thereby connected in series with the filament 23, although they may, if desired, be connected in multiple with the filament 23 by providing suitable additional conductors.

The v-shaped filament 23 is preferably made in the form of a coiled-coil of tungsten wire and is preferably designed to operate at about 1300 C. to closely simulate the brightness of a true candle flame, although it may be operated at The said stay rod i8 has fused to its higher temperatures if desired. The filaments 26 and 21 are preferably made from short helical coils which are greatly stretched out so as to have a slightly wavy contour. The said filament 26 and 21 may be additionally supported by wires 28, 28. having their ends embedded in a glass bead 29 attached to stay rod i8. In the case of a short lamp, the said support wires 28 may be omitted, but in the case of a long lamp, additional support wires 28 may be provided along the length of the stay rod I8.

Another feature of the lamp is the provision of resilient spacer and vibration-preventing means which may consist, as shown in the drawing, of

three or more (six, for example) springy wires 30 which are equally spaced and each of which has one end embedded in the glass rod l9 and the other end bearing against the walls'of the envelope I 0. The ends of the wires 30 bearing against the envelope may have hooks bent in a plane transverse of the lamp axis;

In constructing the lamp, after the envelope portions l0 and II have been fused together, the mount (including the stem i4 and filaments 23,

'26, 21, and their supporting structure) is inserted into the envelope through the lower open end thereof, the'filament 23 being guided through the filament 23 may 'of the said wires 1 constricted neck I2 by the resilient spacer or guide wires 30. This function of the spacer wires 30 is an important one, especially 'where the envelope ill is of considerable length, since it prevents the filament 23 from being against the neck l2 and being thereby bent or otherwise damaged. After the mount has been inserted, the end of the stem I4 is sealed to the lower end of envelope II], the envelope is exhausted and the base 3| attached thereto.

The flame-shaped portion ll of the envelope is preferably made of clear glass so that the outline of the fllament'23 may be readily seen. The body portion H], on the other hand, is preferably made difiusing or colored, for example, by frosting it or by coating it with paint or enamel of any desirable color. When enamel is employed it 'is applied only to the tubular sides of the envelope l6 and not to any portion of the end l3 which is left clear. That is, the envelope portions ll, 20 and I3 are not coated.

It will be noted that the lower end of filament 23 terminates a short distance above the neck l2 while the upper ends of filaments 26, 21 terminate a short distance below the neck l2. This is also an important feature since it means that the neck l2 will be comparatively dark and will therefore correspond to the darksection of a candle wick below the flame and above the wax cup. The lamp is provided with a screw base 3| which is preferably provided with a resilient end contact 32 of any suitable design. In this case, the end contact 32 is-shown as a U-shaped metal spring. The spring 32 assures contact with the center contact of the socket into which the lamp is inserted while permitting a substantial degree of rotation of the lamp so that the plane of the be set to face in any desired direction. The said base is at least as large as the tubular envelope portion 16 to permit the base to completely enter the socket shell and thereby preserve the appearance of a candle.

The modified mount construction shown in Fig. 4 may .be employed, if desired. In this case, the spacer or guide wires 30 of Fig. 1 may be eliminated'and the collar or button 20 may be of slightly smaller diameter than the neck portion 12 of the envelope so that it serves to align the mount within the envelope and prevent vibration thereof), Of course, the spacer wires 30 may additionally be used, if desired.

The modified construction shown in Fig. 5 is preferably used in shorter lamps. In this case, the filaments 26, 21 have been omitted and the lead-in wires 15- and I6 extend all the way 7 through the envelope portion 10, and the ends of the filament 23 are connected directly to the upper ends of said lead-in wires I5, 16. Portions 5, l6 adjacent their upper ends are fused to the rim of the glass button 20. A longer stem 14 may be employed in this case because of the absence of a filament in the envelope portion which would cause a shadow to be cast by the long stem.

The lamp shown in Fig. 6 is somewhat similar to that shown in Fig. 1 except that it is provided with a built-in interrupter '33, the stayrod l8 being provided with an offset portion 34 to provide space for, and to serve as a support for, the said interrupter. The interrupter herein illustrated is a thermal glow switch of the type disclosed in application Serial No. 289,897, W. C. Smitley, filed August 12, 1939. The said switch comprises a sealed glass envelope containing an pushed sic ionizable atmosphere such as neon or argon. The

envelope also contains a pair of electrodes 35, 36

' is attached to a lead-in wire 31 and the other electrode 36 is attached to another lead-in wire 38. The lead-in wire 31 is connected to the lamp lead'wire l5 and the lead wire 38 is connected to a'conductor 39 which is connected .to one end of the filament 23.

When current is supplied to the lamp shown in Fig. 7, the filament 23 is lighted and a potential is appliedacross the electrodes 35 and 36 of the switch 33 which results in a glow discharge therebetween. The glow discharge heats the bimetallic electrode 35 so that the free end thereof is deflected away from the electrode '36 until the V-shaped portion 40 of a contact member ll engages the electrode 36. This causes slightly more current to flow through the filament 23 and also causes the glow discharge to be inter-.- rupted with consequent cooling of the bimetallic electrodev 35 and separation of the contact 4| from the electrode 36. As soon as this contact has been broken, the glow discharge is reestablished. The rapid repetition of this cycle of operation causes a flickering light to be emitted by the filament 23 which very closely simulates the flickering of a real candle flame. The interrupter or switch member 33 may be mounted in thebase 3| or even entirely outside the lamp, for example, in=the socket or in an adapter.

While I have described certain preferred species of my invention, it will be apparent that various modifications may be made within the scope of my invention. For instance, the envelope l6ll may be made in one piece, although the two-piece construction is preferred. Where the body filaments 26-21 are used, they maybe made of molybdenum and operated at about 1170 C. although'tungsten filaments may be used, if desired.

What I claim as new and desire to secure by Letters Patent of the United Staltes is: v

4 1. An electric incandescent lamp comprising an elongated envelope divided into upper and lower chambers by a constricted neck portion, a mount sealed into said envelope and comprising an elongated support member secured at its lower end to a portion of the lower end of said envelope, resilient spacer means secured to said support member within said lower chamber ad.- jacent said neck portion of the envelope and engaging the walls of the envelope, and a filamentlocated within the upper chamber of the envelope, said filament being supported from said support member.

2. An electric incandescent lamp comprising an elongated envelope divided into upper and lower chambers by a constricted neck portion, a

stem sealed to the lower end of said envelope, a I

supporting stay member secured to said stem and extending through the lower chamber of said envelope, said stay member terminating at its upper end in a collar portion located within said constricted neck portion of the envelope, and a filament located. within the upper chamber of the envelope, said filament being supported from said support member.

3. An electric incandescent lamp comprising an elongated envelope divided into upper and lower chambers by a constricted neck portion, a mount sealed into" said envelope and comprising an elongated support member secured at its lower end to a portion ofthe lowerend of said envelope, a collar portion on said support member located within said constricted neck portion of the envelope, said collar portion being of slightly smaller diameter than the said constricted neck portion of the envelope, and a filament located within the upper chamber of the envelope, said filament being supported from said support member. v

4. An electric incandescent lamp comprising an elongated envelope divided into upper and lower chambers by a constricted'neck portion, a mount sealed into said envelope and comprising an elongated support member secured at its lower end to a portion of the lower end of said envelope, a collar portion on said'support member located within said constricted neck portion of the envelope, said collar portion being of slightly smaller diameter than the said constricted neck portion of the envelope, a filament located within the upper chamber of the envelope and support wires extending from said collar portion and engaging said filament.

5. An imitation candle lamp comprising an envelope having an elongated tubular body portion and a flame-shaped upper end portion joined together by a short tubular neck portion of constricted diameter, an inverted V-shaped filament in said flame-shaped bulb portion terminating a short distance above said constricted neck portion, and an elongated filament extending longitudinally of said body-portion of the envelope and terminating a short distance below the said constricted neck portion, the said neck portion itself being devoid of a filament so that it is comparatively dark when the lamp is lighted.

6. An imitation candle lamp comprising an envelope having an elongated tubular body portion and a flame-shaped upper end portion joined,

together by a short tubular neck portion of constricted diameter, an elongated support member secured at its lower end to a portion of the lower end of said envelope and terminating at its upper end substantially within said neck portion, and an inverted V-shaped filament in said fiameshaped bulb portion supported from said upper end of said support member and terminating a short distance above said constricted neck portion, the said neck portion itself being'devoid of a filament so that it is comparatively dark when the lamp i lighted.

7. The method of manufacturing an incandescent lampwhich comprises forming an elongated envelope having a chamber at one end joined to the elongated body portion by a constricted neck portion, forming a mount with a filament thereon so dimensioned as to pass through said neck portion, providing the mount with spacer means adapted to engage the walls of the said body portion of the envelope, and

' said glass upper end gaging the walls of the envelope, and a filament located within the upper chamber of the envelope, said filament being supported from said support member.

9. An imitation candle lamp comprising an envelope having an elongated body portion and a flame-shaped upper end portion joined toge'ther by a 'short tubular neck portion of constricted diameter, a stem sealed to the lower end of said body portion of the envelope, an elongated-support member secured to said stem and extending through said body portion of the envelope, at least the upper end portion of said support member being of glass and terminating substantially within said neck portion of the envelope, support wires sealed to said glass upper end portion of said support member and extending'into the upper end portion of said envelope, and a filament mounted on said support wires within the said upper end portion of the envelope.

10. An imitation candle lamp comprising an envelope having an elongated body portion and a flame-shaped upper end portion joined together by a short tubular heck portion of constricted diameter, a stem sealed to the lower end of said body portion of the envelope, an elongated support member secured to said stem and extending through said body portion of the envelope, at least the upper end portion of said support member being of glass and terminating substantially within said neck portion of the envelope, support wires sealed to said glass upper end portion of said support member andextend ing into the upper end portion of said envelope, a filament mounted on said support wires within the said upper end portion of the envelope, and

current lead-in conductors sealed through said stem and electrically connected to the ends of said filament.

11. An imitation candle lamp comprising an envelope having an elongated body portion and a flame-shaped upper end portion joined together by a short tubular neck portion of constricted diameter, a stem sealed to the lower end of said body portion of the envelope, an elongated support member secured to said stem and extending through said body portion of the envelope, at least the upper end portion of said support.

member being of glass and terminating substantially within said neck portion of the envelope, support wires sealed to said glass upper end portion of saidsupport member and extending into the upper end portion of said envelope, 9, filament mounted on said support wires within the said upper end portion of the envelope, and current lead-in conductors sealed through said stem and extending through said body portion of the envelope, said lead-in conductors having their ends connected to the ends of said filament and having intermediate portions thereof secured to portion of said support member.

12. An imitation candle lamp comprising an envelope having an elongated body portion and a flame-shaped upper end portion joined together by a short tubular neck portion of constricted diameter, a stem sealed to the lower end of said er end to a portion of the lower end of said envelope and terminating at its upper end substantially within said neck portion of the envelope, resilient spacer wires secured to said sup port member within said lower chamber adjabody portion of the envelope, an elongated support member secured to said stem and. extending through said body portion of the envelope, at least the upper end portion of said support member being of glass and terminating substantially within said neck portion of the envelope, support wires sealed to said glass upper end portion of cent said neck portion of the envelope and ensaid support member and extending into the upper end portion of said envelope,a filament mounted on said support wires within the said of said filament and serve to conduct current thereto.

13. An imitation candle lamp comprising an envelope having an elongated body portion and a flame-shaped upper end portion joined together by a short tubular neck portion of constricted diameter, a stem sealed to the lower end of said body portion of the-envelope, an elongated support member secured to said stem and extending through said body portion of the envelope, at least the upper end portion of said support member being of glass and terminating substantially within said neck portion of the envelope, support wires sealed to said glass upper end portion of said support member and extending into the upper end portion of said envelope, current lead-in conductors sealed through said stem, and an additional pair of filaments connected between said lead-in conductorsand a pair of said support wires which are, in turn, connected to the ends of said first-mentioned filament and serve to conduct current thereto.

14. An imitation candle lamp comprising an envelope having an elongated body portion and a flame-shaped upper end portion joined together by a short tubular neck portion of constricted diameter, a stem sealed to the lower end of said body portion of the envelope, an elongated support member secured to said stem and extending through said body portion of the envelope, at least the upper end portion of said support member being of glass .and terminating substantially within said neck portion of the envelope, support wires sealed to said glass upper end portion of said support member and extending into the upper end portion of said envelope, a filament mounted on said support wires within the said upper end portion of the envelope, and resilient spacer wires secured to said glass upper end portion of support member and engaging the walls of the body portion of said envelope.

WILLIAM P. ZABEL. 

